hotels.com 20% anniversary sale - book using your mastercard

Hi,

Not sure how this is going to work saw it in some other website. I searched but didn't find it posted.

Hotels.com [hotels.com]offers a free night at select hotels and takes $20 off a future stay when you book using your MasterCard card and use coupon code "ANNIVERSARY". You must complete your original stay by December 15. You'll then receive the $20 off coupon code six weeks later, which will be good for a stay completed by April 15, 2012. Some restrictions and conditions may apply. Deal ends August 20.

coupon code "ANNIVERSARY" and book using your MasterCard card

Terms and Conditions: Book on the US or Canadian Hotels.com sites by August 20, 2011 date for travel between August 1 – December 15, 2011. Offers and sales on participating properties only. Minimum night stay may be required.
Free Night: You will receive the value of a free night when you book the required number of nights at a participating hotel. For example, when you book four nights at a participating hotel that requires a 4+ night stay, you will receive 25% off of your entire stay, which is the same as receiving a free night.
$20 Credit: To get a $20 credit towards your next stay, you must book a stay at a participating property using your MasterCard card and use coupon code ANNIVERSARY during checkout. Credit will be delivered via email address used at booking within six (6) weeks after the completed travel dates. $20 coupon must be used for a hotel stay by April 30, 2012.
General: Offers vary by property. Rooms and prices are subject to availability. Prices do not include taxes and fees and are subject to change without notice. Additional restrictions and blackout dates may apply.

Thanks moon_2100 and JoshMcMadMac

OP should add Terms and conditions too. Here are terms

Terms and Conditions: Book on the US or Canadian Hotels.com sites by August 20, 2011 date for travel between August 1 – December 15, 2011. Offers and sales on participating properties only. Minimum night stay may be required.
Free Night: You will receive the value of a free night when you book the required number of nights at a participating hotel. For example, when you book four nights at a participating hotel that requires a 4+ night stay, you will receive 25% off of your entire stay, which is the same as receiving a free night.
$20 Credit: To get a $20 credit towards your next stay, you must book a stay at a participating property using your MasterCard card and use coupon code ANNIVERSARY during checkout. Credit will be delivered via email address used at booking within six (6) weeks after the completed travel dates. $20 coupon must be used for a hotel stay by April 30, 2012.
General: Offers vary by property. Rooms and prices are subject to availability. Prices do not include taxes and fees and are subject to change without notice. Additional restrictions and blackout dates may apply.